The create, update, and delete methods had incompatible signatures
resulting in typecheck errors. Renamed to create_book, update_book, and
delete_books.
The Darwin epub test cases used absolute paths. I hadn't notices until switching machines, whcih caused errors in the test harness. Changed to relative paths to be consistent with other test cases.
Updated book progress model in anticipation of the KOReader sync
feature.
Renamed properties:
- renamed "progress" to "percentage"
- renamed "pdf_loc" to "pdf_page"
- renamed "epub_loc" to "epub_cfi"
New properties:
- "epub_xpointer", marks the location of an epub in KOReader
- "device", the device type that updated the progress
- "device_id", the id of the device that updated the progress
